Conventional cathode ray tube (CRT) displays are unsuitable for use in multimedia applications because of their large volume. Therefore, many flat panel display techniques such as liquid crystal display (LCD), plasma display panel (PDP), and field emission display (FED) have been recently developed. These display techniques can manufacture a thin, light, short and small monitor, and thus these techniques are and will be the mainstream technology. In these techniques, the plasma display panel (PDP) is attracting attention in the field of displays as a full-color display apparatus having a large size display area and is especially popularly utilized in large-size televisions or outdoor display panels. This is because it is a high quality display as a result of it being a self-light emitting type with a wide angle of visibility and high speed of response as well as being suited to upsizing due to a simple manufacturing process.
A color PDP is a display in which ultraviolet rays are produced by gas discharge to excite phosphorus so that visible light is emitted therefrom to perform a display operation. Depending upon a discharge mode, the color PDP is classified as an alternating current (AC) or a direct current (DC) type. In the AC-type PDP, an electrode is covered with a protective layer. The AC-type PDP has inherent characteristics of long life and high brightness. Therefore, the AC-type PDP is generally superior to the DC-type PDP in luminance, luminous efficiency and lifetime.
PDP utilizes an external voltage to cause gas discharge inside the panel to produce the ultraviolet rays. The ultraviolet rays excite R, G, and B phosphorus to generate the visible R, G, and B lights. Therefore, the reddish orange color light caused by the gas discharge and the chromaticity purity of R, G, and B phosphorus apparently influences the output color of the PDP module. A good white balance of the PDP module is very important to produce a good color display so the balance of fundamental colors emitted by the R, G, and B phosphorus is important. However, even if a surface filter of the PDP module can filter the reddish orange color and modify the chromaticity of the PDP output, the color space of the PDP module still is different from the color space of the video specification, such as National Television System Committee (NTSC), European Broadcasting Union (EBU) or Standard RGB (sRGB). If there is not sufficient color space transformation, the output color of the PDP module may display visible color deviation. For example, the sky may be too green and a white cloud may be too yellow in a conventional PDP module. In particular, if the image quality is very bad, skin color may become too red or too green when the video specification of the PDP module and the video image signals are different.
The color deviation problem caused by the actual luminous efficiencies of the three fundamental colors of the PDP does not fit the correct luminance ratio requirement; that is, a gray level white balance error exists. Some conventional plasma display panels utilize a nonsymmetrical pixel technology to improve the white balance problem so that the discharge cells are formed in different sizes and the address electrodes are also formed in different widths. Therefore, the manufacture process difficulties and the cost are increased and furthermore the nonlinear luminous efficiency decay of the PDP still exists. Another conventional plasma display panel adjusts the driving frequency to improve the white balance problem by diagnosing the display load factor. Therefore, the electric circuit thereof is more complicates and expensive due to more complicated determination of electric circuits with determining theories. Therefore, there is a need to provide a plasma display panel which can achieve a satisfying gray level white balance thereof so as to reduce the color deviation thereof.